


Sympathy for the Devil

by bitfibber



Category: Adventure Time
Genre: AU, Adventure, Alternate Universe, Animal Death, Demons, F/F, Needles, Romance, Self-Harm, Slow Burn, Tattoos, Violence, Witchcraft
Language: English
Status: In-Progress
Published: 2018-01-24
Updated: 2018-01-24
Packaged: 2019-03-08 22:02:45
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,677
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13467474
Author URL: https://archiveofourown.org/users/bitfibber/pseuds/bitfibber
Summary: (AU) Unnaturally gifted and growing ever more frustrated with her mentors inadequate teaching, sorcerer's apprentice Bonnibel summons the powerful demon Marceline Abadeer with the intent the use her power to escape the swamp, achieve her dreams, and garner the respect she deserves from her peers. However, the demon has an agenda of her own and is only too pleased to have been called by what she initially thinks is a foolish brat. Time to negotiate their differences is short, though, as danger from both of their worlds is closing in on them both.





	Sympathy for the Devil

**Author's Note:**

> I will probably alternate between updating this fic and gold dust women.
> 
> Shoutout to the Rolling Stones for the inspiration.

After making sure he ate all his soup, a young woman with ginger hair lead the old sorcerer by the elbow from the table towards his chair by the fire. He shuffled across the woven reeds covering the dirt floor sleepily, obedient due to a full belly and the tiny dose of sleeping shade she slipped into his portion of dinner.

The leather chair was plush but worn, as the old man had taken to simply sleeping in the chair rather than trekking up the ladder to his lofted bed above the shelves. Here next to the warm hearth, surrounded by the stacks of his personal library, was the best place for the Mage Petrikov to rest his old bones regardless.

She held his hands as he slowly bent his knees and sank backwards into the chair, and then fussed briefly with the folds of his blue robe. Turning to the rack on her right, she grabbed the thick, heavy velvet fabric of his cloak and laid it over him, tucking the hood behind one of the mage’s shoulders. Once a bright fuchsia color distinguishing the mage Simon Petrikov as an archmage capable of the greatest skill and craft, the floor length cloak was now mostly stained a dark wine-like color and the velvet worn, and all of the former ornate designs faded away. It was brown and caked with mud and dirt at the bottom, where it brushed across the ground when worn on his shoulders, but in recent months it was mostly used as a blanket. In contrast, the bright cerulean blue of the linen half-cloak worn by the woman showed no signs of dirt or wear, as she frequently cleaned it with a fastidious and almost loathing fervor. At twenty-five years, she was older than the average sorcerer’s apprentice and so she found herself filled with equal parts pride and loathing: loathing for her lack of mobility through the ranks and pride for being a witch in the first place.

Simon murmured to himself and his black, bony fingers felt the edge of the velvet as he closed his eyes, breathing evenly. His apprentice backed away quietly across the room and then hovered in the doorway to her own room, waiting for his breathing to turn into gentle snores. When they did, Bonnibel ducked under the sagging doorway and dropped the cloth ‘door’ across the opening.

“ _Silentii claustra_.” She muttered, flicking her left pinky at the cloth, the basic sound barrier spell leaving her finger with a prick of pain she didn’t even register.

Inside her quarters, numerous candles floated towards her, the spell that animated them compelled them to illuminate her immediate surroundings. The room was spacious enough unfilled, but various books and magical objects consumed the space, leaving it with a cramped impression. Makeshift shelves made from thick oak boards held apart horizontally by heavy rectangular stones pillaged from a ruin nearby covered most of the walls, the centers of the boards sagging heavily from the weight. The books set upon them varied greatly in size, and so filled the shelves haphazardly and without much order. Most of the books had been stolen from her mentor’s library in truth, the image of them replaced by a simple illusion spell she had perfected years ago back when she only stole one book at a time.

To the left, the shelves broke into a row of waist-high tables covered in various pieces of glassware filled with liquids and distillations where she brewed potions, crafted magical components, and prepared her ink. On a single long shelf above her glassware, a diverse set of stock solutions, jars of paste, and caged small animals sat waiting to be used. One of the tables had a hole cut from it and replaced with a shallow, concave disk of thin metal, punched with small holes for airflow to create a makeshift stove. Within it, a few coals glowed hot, their heat causing a beaker of dark black liquid suspended above on a wire frame to steam. A hollow metal rod sharpened into a long needle at one end soaked in a small glass of clear peroxide solution next to desk-stove, bubbles rising from the edge.

To the right, a neatly made bed sat on rickety wooden stilts above a large wooden desk covered in papers, quills, inkwells, and open books. The ceiling of her room was sloped up into a point and had a large mesh tacked up onto it, a plethora of herbs and plants tied to it for drying and later use. A large woven reed mat, trampled flat by her pacing, covered the dirt floor in her room as well. Immediately next to the door she entered, the mirror image of the hearth in her mentor’s library burned a healthy fire, sharing the same chimney. A set of hearth tools leaned against the stone and a small cauldron hooked on a swing stake sat empty nearby.

The red-haired witch hummed to herself and walked towards the beaker of steaming black ink. She gestured to a book on her desk and it flew towards her, catching it easily in her left hand. Eight inches tall and five inches wide and bound in plain brown leather, the book served as her personal journal for notes, the 25th in a series of blank books she had filled to the brim since she began recording her thoughts and spell preparation notes when she first arrived at Simon’s at 16.

Bonnibel thumbed through the book to the most recent page, then gestured absently at two spare boards of wood leaning against her desk. They sprang to life, zooming across the space and forming a sort of rotating staircase for the young witch as she stepped up them towards the ceiling. There, she plucked a dry pink flower from a single stem of oleander and a clump of tiny white flowers from a bundle of water hemlock, and then descended.

She set everything down next to her desk stove, and then added a small bundle of twigs to the coals beneath the beaker. While waiting for the ink to come to a boil, she rolled the fragile flowers in her hands over the beaker, crushing them and letting the powder float down into the black ink.

When the ink was boiling, she looked up to the shelf. A cage of thin mesh, the bottom covered in straw, held a serpent with golden eyes focused on her own. The snake had a thick body for it’s length and its scales were black along its spine, lightening around its body until the belly scales were only overcast grey. It was a black-mouthed adder, one of the most poisonous and certainly most aggressive species of snakes known to human kind. It took Bonnibel years to finally catch one, as they were exceedingly rare and notoriously difficult to catch alive due to their natural resistance to magic.

Black-mouthed adder blood was also a key ingredient in the creation of the most potent version of black magic spellcasting ink.

Bonnibel lifted the cage from the shelf by the handle; a bite now would mean certain death, for Simon was in no condition to help her anymore. She took a wooden dowel, cut from an old broom handle, and pressed it down laterally over the soft mesh cage, which bent easily under pressure. The dowel came down just behind the serpent’s head and, after a brief struggle where she almost thought it would escape, it was trapped enough for her quickly open the back hatch of the cage and grip it firmly by the neck.

The snake struggled immensely, especially after she lifted the dowel and only her hand remained. It was strikingly powerful, its thick body made of corded muscle, and she sucked in a nervous breath as she fought it and drew it out from the cage over to the beaker.

Holding the snake with her right had, the witch fumbled briefly with her left hand to put a ring over the middle finger of the same hand. The ring was made of plain iron, but had a nub of metal on the underside, which had been hammered flat and sharpened into a tiny blade, positioned perpendicular to her fingers. Bonnibel gripped the snake just below her right hand, squeezing until the blade punctured the snake’s underbelly just below its jaw. The snake thrashed in pain and, not wanting to torture the creature any longer, the apprentice ran her left hand down the length of the adders body, flaying it open from neck to tail. She stopped at its tail and held it firmly so that it couldn’t thrash blood everywhere, blood gushing forth from the long cut and dousing her hand before spilling into the ink.

The adder died her hands. Once the blood had slowed to a trickle, she brought the body over to a metal tray one table over and quickly began to dissect out the other pieces of the snake, storing each in a sterile glass jar of preservation fluid. For the venom, arguably the most valuable part of the animal, she gently pressed the exposed gland with its fangs held over a funnel leading to a tiny glass vial. She sealed it immediately with a cork, and then left the corpse where it was. Intending to clean the bones and other pieces later, she leaned down to a pail of clean water next to her bench and dipped a bowl in it. She set the bowl on the table and then thoroughly washed away the blood caking her hands, the water turning red.

By now, the small fire below the beaker of ink was spent, and the ink no longer boiled but was still plenty hot. She raised her left hand, the skin black and blue and dark red with magic ink up her entire forearm, and waved at the beaker saying, “ _Frigus_.”

The ink cooled immediately. Cocking her tattooed hand over the beaker, she took a deep breath and spoke, “ _effundam magicae sunt et mundamini_.” Runes suddenly glowed red along her ring finger, before fading away almost immediately. The black liquid hissed and shrank, concentrating until it was less than a fourth the total volume and viscous, almost like a jelly. She poured it out into a funnel covered with mesh above a small metal flask, no bigger than a card. It dripped slowly through sieve, leaving chunks of coagulated snake blood and other matter behind.

She leaned down and untied her left boot, and then stripped off her pants most of the way, finally shucking her cowl and tunic. Then, she removed the funnel and moved to sit on a small wooden stool next to the stove. As she plucked the hollow needle up from the peroxide and dried it off, she whistled and her journal floated over to her, as well as another, larger journal bound in blue linen.

The apprentice flipped Simon’s old journal to a page somewhere in the middle. The page was mostly covered in his nigh illegible scrawl, but in the center of the page a diagram of complicated shapes with runes weaving in and out of them was carefully and precisely drawn. She studied it for a moment, and then gestured to a small mirror shard on her desk. It moved to her quickly and then floated directly in front of her, giving her a clear view of her chest.

Sucking in a breath, Bonnibel dipped the needle in the ink and began to tattoo it straight onto her chest, between her breasts. For eons, sorcery and spells cast by humans had been done so traditionally: by inscribing the runes and symbols required to cast the spell straight onto the body of the caster using ink specifically formulated and imbued for whatever type of magic was being cast. When the spell was cast, the ruins were used and disappeared from the body. Spell runes inscribed closer to the core of the person—on the abdomen, along the spine, on the chest—drew more magic from the person’s body and were stronger.

Spells were often tattooed directly on top of one another, resulting in a collection of ink over time, hence her solidly inked hand and forearm. She had a smattering of tattoos elsewhere as well, including a blotch of ink on the side of her abdomen for a collection of more powerful spells, a choice sloppy few on her right hand, and some down along her lower legs.

Bonnibel was used to tattooing herself, but had never tattooed her own chest before. She had never needed to, until now. It took months to prepare the ink and over a year to collect the right ingredients, but tonight the witch was finally ready to summon a demon.

In truth, she’d already summoned a demon before, but she hardly thought a lesser imp counted. Binding lesser imps, the relatively harmless but mischievous fodder at the bottom of the demon food chain, had become somewhat vogue in the more populous cities and a few villagers nearby had inquired about Simon’s prices, but she found them more trouble than they were worth. No demon enjoyed being bound to a mortal, so the imps did their best to complete their assigned tasks (usually housework or errands) with as much deviancy as possible.

But tonight was different. Her sights were aimed far higher than an imp. Over a year ago, months after she had grown bold enough to start rifling through Simon’s personal journals and notes, she discovered something incredible: Simon had once summoned a dremora or middle-rank, or something of similar. Little was known about the hierarchy of the Underworld, so it was hard to infer exactly how powerful this being was, or anything remotely detailed about it. The books on demonology that Simon owned were initially limited, but in general the wizarding community regarded the summoning and binding of powerful demons deeply unethical due to the equally increased opportunities and risk associated with it, not to mention the danger involved with the summoning process in the first place. To snatch demon from the underworld, the summoner must know it’s true name. While a basic imp’s true name might be scried in less than an hour, more powerful demons guarded their true names with profound caution and secrecy.

Simon’s writings suggested that the demon was a large Source of magic and an excellent servant for otherwise unachievable goals, however, so Bonnibel figured it must be fairly high-ranking. If the timing of the entries were correct, then the demon had been bound to him during the time in which he had risen to fame. Those times were long forgotten by the sorcery community now, but his apprentice strongly suspected that this demon was integral to his success.

Now, unable to keep Simon lucid long enough for him to allow her to undergo the rights of passage needed to be a fully-fledged brown-cloaked mage, she hoped that binding this demon of his to herself would grant her enough power to leave this place and earn her cloak her own way. 

Bonnibel sat up with a large sigh, wiping the sweat from her brow with the back of her blackened hand. After several hours, she had finally finished the tattoos she would need: the main summoning spell on her chest and its siblings on the inside of her forearms, a multitude of powerful protection and submission spells on the side of her abdomen and lastly, a contingency spell of her design hidden on the inside of her thigh. Should things go terribly wrong with the demon, she could use it to kill it and (if her spell design was accurate) live to tell the tale.

Blood welled from the puncture wounds, mixing with the acrid smelling ink. Bonnibel pulled a linen cloth from her benchtop and gently dabbed at the five tattooed areas, then gestured and murmered, “ _suo,_ ” watching as the tiny puncture wounds shut almost immediately. She stood and dressed.

It surely must have been the very early hours of the next day and she should sleep, yes, but Bonnibel did not feel tired. Instead, she felt her whole body humming with excitement. ‘ _I am so close_ ,’ she thought, ‘ _Surely I can’t wait until tomorrow night for this_.’

Fully convinced, she moved to the reed mat in the center of the room began to roll it up (she never bothered to enchant it). Beneath it, a large circle with a pentagram had been dug and filled with salt. A diamond, ruby, amethyst, emerald, and topaz each dotted one of the five corners of the inverted star. Inside the pentagram, the pentagon shape was carefully covered in a bed of dried oak leaves.

Standing at the edge of the circle in a salt triangle of her own, Bonnibel knew there was only one thing missing. “ _Huc_ , Grimoire,” she had only just uttered the phrase but the witch barely had time to catch the book by it’s spine as it flew from her desk straight for her head.

She smoothed her untattooed hand over the cover of the book, feeling the unbelievably soft black leather. Bonnibel strongly suspected it was made from the skin of a demon; as for the interior, she was certain that the thin pages were vellum made from human skin. There was no title on the front of the book, just a carving of a huge eye, lacking lashes and lids and so it had taken several weeks to identify the book. As she looked at it, she had the strangest feeling that she was being watched. The old mage didn’t keep the black book of demonology on his usual shelves; instead, she found it locked in a flat chest beneath the floorboards in his room, possibly to prevent instances just like this one. A profoundly old and legendary text, the Grimoire was known mostly thought of as a myth these days, so perhaps this was the perk of having an incredibly old mentor. It contained not only detailed information on demonkind, but also the exact instructions for summoning every kind of demon, including the King of the Underworld himself, provided you knew his true name and had a death wish. It was this book she would read the incantation from.

Flipping the book open to the page with the proper incantation, Bonnibel held the book up in the air and then let go, watching as it hovered in mid air in front of her, eager to continue as though it had a will of its own.

With one last glance at the text, Bonnibel steeled herself and then shouted out the spell, “ _Maloso vobiscum et cum spiritum, advocabit Melinoë et obligaverit mihi!"_  

Pain seared across her chest and wrists, as though someone slashed into the thin skin over her sternum with a red-hot knife. A blaring noise, like thousands of howling dogs, suddenly filled the room, deafening her. She screamed with the room and, for a moment, she thought to herself that this was perhaps the worst pain she had ever experienced. That thought was quickly silenced as the pain from the runes faded as quickly as they flared and the magical drain of the spell came to her attention.

She doubled over and let her knees buckle beneath her, her body slumping to the dirt like a sack of potatoes. The spell drained the magic from her body almost immediately, and then began to drain her life force. Although this pain wasn’t nearly as acute as the loss of the rune, the deep and unrelenting ache as she began to die was unbearable. It felt as though someone was pulling her intestines out through her belly button, and she was powerless to stop it. The witch wanted to vomit, but couldn’t will her abdominal muscles to flex.

‘ _This was a mistake._ ’ She realized, ‘ _I’m going to die here, face down in the dirt._ ’

Just as she had finally accepted her death, the howling in the room reached a fever pitch and a foreign wind swept through the room with a final, ringing BOOM! The wind extinguished all of her candles and even doused the fireplace, dropping the room into darkness while candles rained down around her body. The draining of her life came to an abrupt end, and suddenly Bonnibel controlled her body again. She propped herself on her hands and knees and immediately retched onto the ground, and then sat back, legs crossed, and breathed heavily.

A groan split the silence of the darkness, but it hadn’t come from Bonnibel. Her green eyes flew open wide and searched the darkness of the pentagram in front of her; so relieved to have made it through the spell alive, the sorcerer’s apprentice had given no thought to whether or not the summoning actually worked. 

The witch scrambled to her feet and reached her hand to where her candles might be, commanding, “ _Igni!_ ”

Belatedly, she realized that if she had no magic left, even this tiny command could very well kill her. However, rather than drain her own life, the tiny spell drew on a dark and sinister pool of magic she only just now noticed hovering on the edge of her senses, the sensation of it passing through her reminded her of dipping her hands into a cold jelly.

The candles flared into life, launching off the floor and circling the room.

Directly in front her, a naked girl with pale grey skin, pointed ears, and a large mass of black hair lay curled on her side amongst the oak leaves in the center of the pentagram, clutching her wrists. The runes once tattooed on Bonnibel’s chest and forearms now glowed orange on the demon girl’s skin, and then faded. With another groan, the girl rolled over onto her back, giving her summoner her first good look at the demon’s face.

Bonnibels eyes grew wide with surprise and she was struck with a realization: ‘ _She’s beautiful._ ”

**Author's Note:**

> \- Try not to take the latin too seriously… it’s Dog Latin and considering how much research I am doing on demons, I guarantee I won’t be trying to get correct latin grammer.  
> \- “effundam magicae sunt et mundamini” = pour magic and purify. As in, ‘imbue this solution with magic, then purify and concentrate it’  
> \- “Maloso vobiscum et cum spiritum, advocabit Melinoë et obligaverit mihi!” = ‘Evil be with you and with your spirit, summon Melinoë and bind her to me!’ because I am terribly unimaginative. Also the first part of the incantation is what everyone uses to open the Nightosphere doorway in Adventure Time.  
> \- Water hemlock and oleanders are very poisonous to humans.  
> \- The black-mouthed adder is an amalgam of the black mamba and a puff adder.  
> \- Yes, all magic spells have to be stick-and-poke tattooed onto the user’s body. Pretty hardcore, amiright??
> 
> I will basically be pillaging the lore for this story from like 15 different sources and worlds out there. Some of you might remember the Grimoire from Wicked, others might notice that the five gemstones are the only gems available in Diablo III, and so on. 
> 
> Also, I have started a tumblr where I can consume fan content to keep up my interest, answer your questions, and post other thoughts about this world and my other story. It’s bitfibber dot tumblr dot com. Come talk to me. 
> 
> Also, still looking for a beta!


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